TY  - THES
AU  - Ding, Kaining
TI  - Nanostructured Si-alloys for silicon solar cells
VL  - 246
PB  - RWTH Aachen
VL  - Dr.
CY  - Jülich
M1  - FZJ-2015-02356
SN  - 978-3-95806-024-1
T2  - Schriften des Forschungszentrums Jülich Reihe Energie & Umwelt / Energy & Environment
SP  - 210 S.
PY  - 2015
N1  - RWTH Aachen, Diss., 2014
AB  - In order to initiate further progress in silicon (Si) photovoltaics, a next-generation of Si solar cell concepts targeting both high performance and low-cost production needs to emerge. The objective of this thesis is to fabricate and characterize Si nanostructures embedded in a Si alloy matrix and implement these novel materials into Si based photovoltaic devices. In particular, silicon quantum dots (Si-QDs) in asilicon carbide (SiC)/Si-rich silicon oxide (SiO$_{x}$) hetero-superlattice (HSL) structure as top cell absorber in all-Si tandem solar cells and nanocomposite microcrystalline silicon oxide ($\mu$c-SiO$_{x}$:H) as contact layers in silicon heterojunction (SHJ) solar cells have been investigated. The main focus of the Si-QD absorber topic lies on the fundamental understanding of the material properties, whereas for the SHJ solar cell topic, developments on device level are the key aspect. Due to the competing nature of charge carrier confinement requiring high band offset and charge carrier transport demanding low band offset between Si-QDs and the embedding material, the choice of different materials for matrix and barrier is indicated. The novel Si-QD absorber approach based on HSL with near-stoichiometric SiC (low band offset) as vertical barrier layer and Si-rich SiO$_{x}$ (high band offset) as lateral matrix layer is motivated by pointing out the technical and theoretical diffculties of Si-QD formation in SiC matrix. After the successful development of laterally uniform, low rate and fully compatible plasma-enhanced chemical vapor depositions of high quality SiC and SiO$_{x}$ single layers, the processes were transfered into an automatic deposition sequence, which allows for the fabrication of SiC/SiO$_{x}$ HSL structures with excellent control over the sublayer composition and thickness. Even though the SiO$_{x}$ was found to fulfill the requirements for a matrix material upon high-temperature annealing (Si precipitation and crystallization, well passivated Si-QDs exhibiting clear signature of quantum confinement, remaining [...]
KW  - Dissertation (GND)
LB  - PUB:(DE-HGF)11 ; PUB:(DE-HGF)3
UR  - https://juser.fz-juelich.de/record/189156
ER  -